774
I have a slight suspicion that it is a scam
(file.coffee)
Never pay another DVD rewind fee again! Compatible with all disc formats: DVD-R, DVD-RW, DVD+R, DVD+RW, CDR, CDRW, Audio CD, VCD. Multi-region, code-free rewinder capable of rewinding all 6 region DVD's including RCE/REA encoded discs
There was still a wear layer below the data layer which could be resurfaced. So the services worked.
Commonly it worked by removing some material from the bottom wear layer to remove the damaged bits, so it didn't work forever. You would eventually run out of material to remove and trying to repair it would result in a catastrophic failure of the media.
Writable disks however, not so good.